redux - state structure change

deriveState.js

/* other derived state methods */

const moveToApp = state =>
  Object.defineProperties(state, {
    users: {
      get: function() {
        return this.app.users;
      },
      enumerable: false,
      configurable: true
    },
    books: {
      get: function() {
        return this.app.books;
      },
      enumerable: false,
      configurable: true
    },
    comments: {
      get: function() {
        return this.app.comments;
      },
      enumerable: false,
      configurable: true
    }
  });

export const deriveState = compose(
  /* ... */ 
  moveToApp
);